In recent years, monitoring of global waterways has become increasingly important. Vehicles that are less conspicuous are often times useful for such monitoring. For example, some small unmanned aerial vehicles (UAVs) are useful for intelligence gathering, surveillance and reconnaissance roles in certain waterways. Conventional UAV's fly in the air and can contain various sensors that perform sensing operations. However, the endurance of UAV's is typically limited, which limits the use of UAV's on global waterways where the distances to be covered are immense, unless a tending ship from which the UAV is launched is present or the UAV is monitoring a waterway close to land.